1. Field of the Invention
This invention relates to a device for applying adhesive tape to inner leads of a semiconductor lead frame for the purpose of preventing the inner leads from falling out of alignment, and more particularly to a device for applying an annularly perforated piece of adhesive tape to all the inner leads of a lead frame having leads which extend outwardly in four general directions.
2. Description of Prior Art
In recent years, semiconductor lead frames have come to assume increasingly complicated configurations and their leads have been gradually growing in number. These lead frames are manufactured by pressing or etching. While they are being pressed or otherwise handled, the inner leads are liable to fall randomly out of alignment. This loss of alignment of the inner leads has caused a disconnection of connector wires when semiconductor pellets are disposed on tabs in lead frames and interconnecting the terminals of pellets and corresponding leads with connector wires or after the stage of resin molding.
to preclude this loss of alignment of the inner leads, it is known to apply to the inner leads, except for the tips thereof which are used for union with connector wires, an insulating tape which is resistant to heat and is incapable of thermal expansion or contraction and which includes an adhesive reagent. This application of an adhesive tape has heretofore been performed either manually or with the aid of a device adapted to apply such tape in parallel to leads extended in two opposite directions, e.g., as disclosed in U.S. Pat. No. 4,279,682. The manual application is disadvantageous because the work is not efficient and the accuracy of finish is appreciably dispersed. The mechanical application has a disadvantage that in the case of a DIP type lead frame a illustrated in FIG. 1, which has long inner leads extending in only two directions, parallel tapes c may be applied to the long inner leads b in a direction substantially perpendicular thereto but, in the case of a flat-packaging lead frame d illustrated in FIG. 2 which has long inner leads extending in four directions, parallel tapes applied only to the leads extending in two parallel directions will not to apply the lead extending perpendicular thereto.
In FIG. 2, e denotes a hole for determining the position of the lead frame d.